Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DNA-directed RNA polymerase from the extremely thermophilic eubacterium Thermus thermophilus HB8 was purified employing a new and rapid method. The subunit pattern of the enzyme, analyzed by SDS gel electrophoresis, was interpreted as: 140 kDa and 170 kDa for beta and beta', 40 kDa for alpha and 92 kDa for sigma. The RNA polymerase is active at elevated temperatures (65 degrees C). Kinetic data provide evidence for the existence of two NTP binding sites with very strong cooperativity. The promoter site specificity of the isolated enzyme has been proven by in vitro transcription employing two T. thermophilus templates whose in vivo starts of transcription were characterized by nuclease S1 mapping.
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PMID:Isolation and physical properties of the DNA-directed RNA polymerase from Thermus thermophilus HB8. 238 94

We have previously shown that plant RNA polymerase II preferentially forms ternary transcription complexes on a cloned fragment of the cauliflower mosaic virus genome in the presence of a particular dinucleotide/purine NTP combination (ApG + ATP). This preferential interaction is observed when the viral sequences are present on a discrete circular molecule. Deletion of a 205-bases-pair region abolishes this selectivity. The deleted region contains a considerable number of symmetrical or repeating elements. The use of nuclease S1 as a probe shows that this region contains a homopurine-homopyrimidine sequence which is extremely sensitive to this enzyme, indicating its capacity to adopt a non-B DNA conformation. A possible alternative structure of these sequences, which may explain the preferential interaction with the RNA polymerase, is presented.
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PMID:Selective dinucleotide-primed in vitro transcription of a cloned fragment of cauliflower mosaic virus DNA is dependent on a limited region of the viral genome. 301 33

Rice tungro disease is caused by a combination of two viruses: rice tungro spherical virus (RTSV) and rice tungro bacilliform virus (Jones et al. (1991) J. Gen. Virol. 72, 757-761.). The genome of RTSV is a single-stranded polyadenylated RNA. We present here the 12,433-nucleotide complete sequence of RTSV genomic RNA and its deduced coding regions. This sequence contains a large open reading frame (ORF) which initiates following a 514-nucleotide 5' leader sequence and is capable of encoding a viral polyprotein of 390.3 kDa. Two viral subgenomic RNAs of ca. 1.2 and 1.4 kb, respectively, were detected in RTSV-infected leaf tissues and mapped by S1 nuclease protection assay. These RNAs were determined to be congruent with the genomic RNA sequence proximal to the 3' terminus and could contain up to two small ORFs in their 5' to 3' orientation. There are at least three capsid protein subunit cistrons near the N-terminus of the large ORF. A computer-aided search of the C-terminal half of the large ORF revealed conserved protein sequence motifs for a viral RNA polymerase, proteinase, and a putative NTP-binding protein. These sequence motifs are arranged in a manner that resembles those of picorna-like viruses. Taken together, these data indicate that RTSV is a distinct type of positive-strand RNA virus. The evolutionary relationships between RTSV and other picorna-like plant viruses are discussed.
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PMID:Nucleotide sequence and genomic organization of rice tungro spherical virus. 846 Apr 78